S Port Dundas

[JimG]

How about getting some flat rubber laser cut with the repeating pattern Jim and attach it to a wooden roller? I've cut a similar thing recently for an "artist" for rolling patterns in clay....

Bob,

That is another possibility.

We had a discussion about the matter at the club last night, including considering doing them all by hand with a scriber/scraper. TimC had done some samplers of his stonework for his buildings and the results looked really good. I had a quick try at doing some setts on a spare piece of DAS that he had, but soon realised that that might not be the best idea for twelve square feet.

I'm also trying to think of a system that will work when fitting the setts in and around all the railway trackwork where I might have to break up the placement into quite irregular chunks to fit round everything - as they did in real life. So if I go too far down the road of a system which will be excellent for doing a large area, like a roller of some form, then I might finish up spending a lot of time trying to make good use of it for the many "funny" areas. Another consideration when drawing up the relatively small size of the die already made was trying to balance a random placement of setts against an obvious repeating pattern.

This could be my project for the year, or should that be years.

Jim.

 

[TimC]

Bob,

........

This could be my project for the year, or should that be years.

Jim.

I think I should print that out and put it on the club noticeboard......

 

[JimG]

I think I should print that out and put it on the club noticeboard......

Maybe I should have used the word "our" .

Jim.

 

[JimG]

I machined up another die this morning leaving the edges off long edge and one short side...



...with the bottom and right side having the spacing ridge left off.



I then had several goes at using it and the results were better, but still not as good as I want. The end joints certainly worked better, but the longitudinal joints showed up fairly obviously. I found out that the problem seems to be that I have to apply a bit of pressure to get a good impression and the DAS tends to create a small, raised dyke around the die, which affects the previous impression. I impressed these setts from top left to bottom right and you can see the effect on the left/upper long sides of the impressions. The problem is also there with the end joints but not quite so pronounced and I found that I could gently pat down a protruding sett.

If I use less pressure, then the problem diminishes, but so does the quality of the impression. The uneven surface within the individual impressions is actually a very good representation of what setts in Glasgow looked like but the obvious long joint line spoils the overall look. (I almost wrote "impression" )

More food for thought, and time to consider some of the other suggestion made.

Jim.

 

[Heather Kay]

Have you considered making a die that let's you make a deeper impression which you could tamp or roll flatter again?

The only other idea I've had was to use the mill to cut the setts into a dried sheet of Das.

 

[JimG]

Have you considered making a die that let's you make a deeper impression which you could tamp or roll flatter again?

The only other idea I've had was to use the mill to cut the setts into a dried sheet of Das.

Heather,

I haven't considered either of those. Milling hardened DAS sheets is a possibility but I would have to use quite small cutters and I'm not sure how long they would last cutting DAS. But I've just rolled out a small slab of DAS on a bit of cling film to try out on the mill when it has hardened.

I'm not sure about making a deeper impression to roll flatter since I find the DAS clay quite soft and malleable and I suspect that it would deform when trying to roll things flatter. I have been thinking of leaving the DAS until it starts to go off when it might not be so soft, but that might take a while until I can assess when the best time might be.

Jim.

 

[TimC]

I've had a productive day scribing DAS. Yesterday at Club I messed around on a scrap piece of DAS I had prepared when I covered the buildings. I tired a number of tools I had to hand but a ball ended scriber-sorta-thing was the best by far. One pass did the scribing job and it is comfortable to hold and can be used with a ruler easily. The tool came from Freestone Models and had been the subject of a blog entry or maybe from a thread somewhere so I got one at the recent Abingdon Show.



Today I set about marking out the stonework on the tall warehouse in pencil. Close examination of the photographs show that it was predominantly large standard sized blocks roughly 2' x 1'.

Before I cut out the next set of plywood frames for the next structures I need to think about the block work first. It took a bit of artists licence to fit the courses together. Thankfully, the adjoining long building to the warehouse has a more random stone pattern.....

Anyway I reckon after about 4 hours I went from plain DAS to 2.5 scribed sides (no need to fill in the section covered by the adjoining building). The benefit of marking out in pencil is that it disappears as you scribe so you can see where you have been or more importantly where not!






There are some areas where I'll have to distress the stone to hide spurious lines and other surface damage that will no doubt stand out once painted.

All in all though not too painful a process.

 

[JimG]

The only other idea I've had was to use the mill to cut the setts into a dried sheet of Das.

Heather,

Your wish is my command.

I rolled out a bit of DAS on Wednesday to about 3mm thick and left it to harden for a couple of days, then stuck it down on the mill table and had a go at it.



...and the first thing I found out was that it is quite difficult to roll DAS completely flat.



I had to keep dropping the cutter by 0.1mm at a time to try to cut the left hand end meanwhile ploughing deeper and deeper into the right hand end.



So I then tried doing a surfacing cut with a 5mm cutter to get a completely flat surface. I wasn't sure how this would turn out - i.e. that the surface would look too flat.



I then cut the pattern again to o.1mm depth with the 0.2mm cutter and cleaned it up and finished it off with a softish glass fibre brush, and it looked not too bad.



I then tried a slightly deeper cut with the 0.2mm cutter, which made a slight difference, but not as much as I thought.

I also had had a discussion with TimC about the setts, and the size of the setts cropped up. I had been aiming for a scale size of 4" wide by between 4" and 12" long. If you apply the three foot rule, then I suspect that these setts will not show so we thought about scaling them up. I had made another sett drawing and I tried upping the size of that and trying it.



First at 0.1mm depth...



...then at 0.2mm depth. It cut quite well but I think I went a bit too big. It is almost 7mm scale size. So I'll have another look at the scaling factor. But overall I was quite pleased with the results. The machined flat surface is not quite so apparent as I thought it might be and the cutter leaves a slightly rough edge to the setts which takes the edge off the machined look, and a bit of brushing with a soft glass fibre brush takes a bit more of the edge off.

I might do a bit more experimenting with the width of the cut. I used a 0.3mm cutter on the larger sized setts and I think I could probably have gone up to 0.4mm, or maybe even 0.5mm. I might also go a bit deeper with the cuts, thinking ahead to when we have to paint and weather the setts, when shallower cuts could fill up with paint.

Since this looks as though it will work, I'm contemplating machining largish sections - maybe up to 6" x 4" - to fit between tracks and between the tracks and the baseboard or building edges, then it could be a fairly quick process to stick them down, like carpet tiles. I've also got all the accurate dimensions of the four foot way from Templot, so I could machine long strips of setts to go between the rails, and also all the "funny" bits to fit in all the areas in the formation.

I also had the idea that I could be doing brickwork for buildings using this method - the CNC answer to laser cutting.

Jim.

 

[Heather Kay]

Wow! That's quite impressive.

To paraphrase "Back to the Future"s Doc Brown, I seem to have come up with something that actually worked!

 

[TimC]

More scribing..... Actually, about 10 hours worth



For this building I wanted a random stone pattern. However, having started to mark it out in pencil, I realised that actually I had no idea if what I was doing was correct or even what basic rules I should be following. A quick search found a document by the City of Glasgow College (Jim will approve!) on bonding for snecked stone walling. While the document is really aimed at using modern cut stone blocks (in 3 sizes) , the basic rules would work fine for a builder with a much more varied selection of stone. Having worked with these, I'm much happier with what I've produced, though it was very time consuming.

I'm not sure what to do next - the roof, the windows or start on the next set of buildings and get them all scribed up too. I'll certainly leave painting them all to the end. Decisions, decisions....

 

[john lewsey]

That is superb really impressed

 

[JimG]

Tim.

Looking extremely good and a lot further on than my setts. I'm churning out another test piece at the moment to try out on Tuesday.

Jim.

 

[Jordan]

The elephant in the room for this layout is the cobbles or, more accurately, the setts. ... .

Good correction - "cobbles" is what we at the Back of the Class would make of the job....


... or is that 'cobblers'...

 

[JimG]

This is a change from kit pictures of etches and castings.



This is a MERG kit to drive four servo motors for point control - the Servo4-F. It is well packaged and comes with a very good set of instructions. It is the easiest way to build a servo controller since someone at MERG has done all the leg work and sourced all the components, got the PCB etched and programmed the PIC chip to do the job. You could do it all yourself, but I would rather pay £6.30 and get the fruits of someone else's labours. I need to operate seven turnouts on Port Dundas, so this is one of two kits purchased to do the job.



Just started on assembly with several of the resistors in and soldered and the diodes fitted and waiting to be soldered in.



The top of the board a bit further on, with the 14 pin DIL socket for the PIC chip just installed.



The instructions are good but I think they require a bit of knowledge about components - like the resistor networks, or, as they are referred to in the instructions, RESNETS. The lower five-pin one has to be fitted with reference to its common pin, marked by a faint white dot which you can just barely see above and slightly to the right of the left hand leg - not the white reflection immediately above the leg.



The board is finished, but the PIC chip is still unfitted until the board is checked out.



The checking is done with a multimeter - this is an inexpensive one I got from Maplins several years ago for about £10 and it does the job well. However, I did find one problem when checking the previous board and found that the regulated voltage was about one volt higher than it should be. I spent ages checking everything to try and find out what the problem was, and eventually dug out another meter which measured the voltage at the correct value. I then found that the nine volt battery in the high reading meter was on its last legs and when I replaced it with a new one this morning, the meter read the voltage properly. So these cheap meters can be fine but maybe not so trustworthy as a more expensive model which would probably have given accuracy warnings with a low battery.

On testing this board I found that there was no 5V supply to the 14 pin PIC socket. The PIC has its own voltage regulator and it didn't take long to track down the fact that this regulator was getting no input voltage, and that the problem was down to this dry joint and the end of the diode feeding the regulator.




A quick touch with the soldering iron and solder soon corrected that.



The last action is to set up the board to control the four servos - the speed and direction of throw and the length of throw. The board is hooked up to my Netbook using a USB to PC Serial lead and the MERG Servoset+ software is run. Each servo's individual settings can be adjusted and stored on the PIC chip. The servo is a Tower SG90 which is the one recommended by MERG and it should have enough torque to operate S scale pointwork.

The next job is to make up turnout operating units incorporating the servos and get the turnouts operating.

This is quite an inexpensive method of operating pointwork. The MERG Servo4 board costs £6.30 (including postage) and the Tower servo costs around £3.00 from various sources. I've seen them as cheap as £8.49 for four on Ebay. Mine cost £3.00 each which gives me a servo drive system for about £4.60 per turnout. You've got to be a MERG members to get the kits, but it could be worth your while joining if you have a lot of pointwork to control.

Jim.

 

[JimG]

Back to the baseboards.

I brought a couple of the boards back from the clubrooms to do more work on them The intention is that the layout folds up with all its buildings into a box for transport and this box will be about 3' x 2' x 2'.

The first thing was to get the back boards on the boards.



The boards are from good 6mm ply salvaged from the skip at my daughter's house after them building an extension to their house. The boards measure 10" high from the baseboards' top surface.



...and the back corner which looks a bit Clydebuilt. At the moment this work is a bit exploratory since I wanted to use as light materials as possible, hence the 6mm ply, to keep the weight down. I was worried about building a box which finished up weighing a "ton" which rather negated all the work on lightweight baseboards. I wanted countersunk screws on the front so that they could be easily disguised under the backscene and I went for 6mm screws to give a reasonable size to avoid pulling through the relatively thin plywood. The alloy angle is from B&Q's metal rack.



The rear of the boards with the hinge in the middle. The piece of wood in the lower foreground hinges up to brace the boards when they are folded over.



...and the boards folded over. The other pair of boards will fold in a similar fashion as a mirror to these boards, then the two parts will hinge round to form the box. The half hinge is at the bottom corner closest to the camera.



The back of the folded boards with the boards latched and the prop in place. Without the prop, the 6mm ply waves about in the breeze, which is what I was worried about when planning the exercise. But the prop does provide a good stiffener which will really only be required when the boards are being folded and unfolded since I intend to have a square cover on each end which will be screwed firmly to the ends and make a firm box structure.



...and the hinge is the old, cheap pasteboard table hinge. Having worked with pasting tables over the years and seen the beating that this design of hinge can take, I think it will probably do the job well. It will only really be under stress in the folding operation and if some care is taken, it shouldn't be too stressed.

I hope to get the other two boards completed over the coming week so that all the main woodwork is done on the layout. One advantage of an all folding layout is that I can carry the inter-baseboard wiring across the hinges so that I don't require plugs and sockets. I'll probably use vehicle cable to get good flexibility life and there will be a screw connector close to each joint so that the boards can be split apart if required.

Jim.

 

[tomstaf]

This looks very well thought out Jim

Cheers

Tom

 

[Susie]

Hi Jim,

Just thinking about your granite sett problem, how about milling another die, but perhaps a bit longer, and then using it to emboss thin damp Bristol board, using a strip of rubber (inner tube) on the back of the card by squeezing the whole lot in a vice? I used the method to produce GNR coach sides in my 2mm scale days, as per Geoff Balfour.

Susie

 

[JimG]

Susie,

I've been experimenting with milling DAS sheet as suggested by Heather a week or two ago and been getting pretty good results. I've got as far as trying to get a thin DAS sheet on a flexible backing to be able to crack and distort it to get more like the typical uneven sett surfaces. I've tried using net curtain material as the backing and I'm going to try very thin cork sheet next since it could be a bit easier to handle.

The setts are a bit on the back burner at the moment since the milling machine is tied up doing other things but I can have a look at doing what you suggest. I haven't used Bristol board for years. We have a good art shop in the town centre so I can see if they have any in stock. I still have the small brass plates I milled up for my first experiments so I could have a quick try with them to see what it looks like. Finding a bit of thin rubber sheet might be more difficult.

Jim.

 

[JimG]

And here's a bit more work done after a bit of a delay. I've just had several weeks of modelling inactivity brought about by what has now been diagnosed as osteoarthritus in my left hip, which is a bit of a show stopper. I couldn't even watch the football and tennis comfortably since sitting was just as bad as standing. However, I'm learning to live with it and I've managed to get a bit more work done on the baseboards in the last week.



The second pair of boards have their backscene panels fitted as a mirror image of the other two, with the same paste board hinge in the middle.



The same strut arrangement is provided. The cutout on the left hand board is for access to the sector plate. There should probably be a cutout as well on the right hand board since the intention is to have a storage road from the sector plate along the back of the board, but there have been discussions about whether we would need this storage road and the sector plate, so I'll wait to see what we decide.



And now the boards are folded up.



I'm now a bit restricted by the size of the worktop on the Workmate, but the board pairs have been coupled up with the hinge and partly swung round to the closed position.



...and are now shown in the closed position.



The boards are held together with two drawbolts on the top and the hinge and one drawbolt on the bottom.

The last job to do is make up two plywood sheet end plates which will be screwed to the two open ends to provide protection and more stiffening. They will also have a handle on each to make carrying easier. I'm also looking at making some detachable wheels to make transporting a bit easier between car and hall.

The size of the folded box is 36" x 28.5" x 24" so it should fit easily in the back of an estate car. At first I had hoped to get it in the back seat of a car, but maybe limousines only.

I'm hoping that one advantage of having all the boards hinged together is that I can dispense with plug and socket connections between boards and have continuous, flexible cabling across the three board joints. I'm thinking about the best way of doing this that doesn't leave loops of cable sticking out when folded up.

Jim.

 

[TimC]

Looking good Jim! Sorry to hear about your hip, hope you are better soon.

Another month and I'll be back too.....